Delivery valve



L. BEEH DELIVERY VALVE May 4, 1943.

2 sheets-sheet 1 Filed Sept. 18, 1942 fyi L l l n l l Y V ggald z INVENToR. oU/s ,EEE/4 BY /fmfm v TToR/VEY Mgy 4, 1943. BEEH 2,318,449

DELIVERY VALVE i gm INVENTOR. 01//3 55H i BY Afm @ma ,4 T TOR/v5 Y Patented May 4, 1943 UNITED STATES PATENT OFFICE DELIVERY VALVE Louis Beeh, Long Meadow, Mass. Application September 18, 1942, SerialNo. 453,803

11 claims. (c1. 251-144) I This invention relates to a delivery valve for hydraulic systems in which a line is periodically passed by quantities of uid under high pressure. Such a system is, for instance, the conventional feeding system of an internal combustion engine of the injection type in which fuel under high pressure is supplied by a metering pump to the injection nozzle of a cylinder of the engine. In my co-pending application Serial No. 409,663 filed September 5 1941, I have more explicitly explained certain` pressure oscillations occurring in the conduit of such a system between the fuel pump and the nozzle and causing harmful secondary and even tertiary injections as a reaction to the abrupt closing of both the nozzle and the delivery valve of the pump, and I have disclosed in that application a new delivery valve with the aid of which such oscillations can be avoided. However, the valve according to that application is useful for the indicated purpose and with the desired result only ii a by-pass is open in connection with the pump or between the pump and the delivery valve immediately after the end of the feeding period. Contrary thereto, the present invention contemplates the provision of a valve whereby the aforementioned pressure oscillations can be avoided or at least minimized regardless of whether or not there is a by-pass in connection with the pump or other source supplying the fluid under high pressure.`

The invention consists of a delivery valve which embodies a by-passing means for the line to which the valve is connected, wherein said bypassing means is operative during the closing period of the valve to relieve the associated line from high pressure. Y

The invention further contemplates the pro'-4 vision and consists of means whereby a valve inserted intermediate the ends of a line and opening in response to a predetermined value of uid pressure originating from the one line end is operative during the closing of the valve owing to a pressure drop in the branch from whoseend the pressure originates to. relieve both li'n'e branches, at least partly, of the pressure remain' ing therein.

Other details and objects of the invention will be apparent from the description given hereinafter and the accompanying drawings illustrating embodiments thereof by way of example.

ln the drawings,

Fig. l is a longitudinal cross-section of an embodiment of the invention, applied to a line between a pump and a nozzle, both shown in a diagrammatical manner.

Figs. 2 to 4 are diagrams showing the valve poppet in different positions, respectively.

Fig. 5 isa longitudinal cross-section of another embodiment.

Fig. 5a. is a sectional view of the poppet of Fig. 5.

Fig. 6 is a cross-section along line 5 5 of Fig. 5.

Fig; 7 is a longitudinal cross-section of a third embodiment, and

Fig. 8 is a cross-section along line 8-8 of Fig. 7.

Referring now to the drawings, the illustrated valve comprises a substantially cylindrical housing I which is open at its top and provided with an internal threading 2 in its upper portion. The housing has two projecting sockets 3 and 4. Socket 3 extends axially downward, and socket 4 projects laterally of the housing. Both are suitably shaped for the attachment of a pipe or conduit' and, for this purpose, are provided with external threadings 6 and 'I, respectively, and with bores 8 and 9, respectively. The bore 8 of socket 3 opens in the bottom surface Ill-of the interior of the housing, and bore 9 communicates with an annular space 5 between the inner housing wall and a plug-like headed body II. Body II comprises an upper externally threaded portion I2 and a cylindrical portion I3, the'lower faceof which seats tightly on the bottom face lil when the body is screwed with a tight t into the threading 2 of the housing. The diameter of the portion I3 is smaller than the inner diameter of the housing so as to form the aforemen` tioned free annular space 5. The head I4 of body I I` is hexagonal for applicationof a wrench when-the parts are to be assembled or dises#4 sembled, and a third socket I5 with externaly threading I5 projects axially from. the head 454,' The body 'II is provided with an axial bore I'I with an extension I8 of smaller diameter reaching upward vapproximately as far as the head I4. Another bore I9 passes slantingly through body portion I2 from space 5 upward so that it interi sects the edge of the bottom 20 of the bore extension I 8, and that a small port 30 exists between the bores I8 and I9. 'Ihere is also a third bore 2| arranged laterally of bore I'I and ,closed at its lower end by the bottom surface Il) of the housing. The upper continuation 22 of bore 2| opens in the top of socket I5. Two spaced passages 23 and 24 at a distance from surface I0 connect bore I 'I with bore 2I. Bore I'I constitutes a cylindrical chamber in which the valve poppet 25 is.y movable. 'Ihe latter is shaped as a plunger with a rod. 26 slidingly engaging in extension I8.

The lower plunger edge is chamfered at 21, so, however, that a central bottom face 28 can seat on surface I and close the bore 8 in socket 3. In this position of the plunger, chamfer 21, surface I0 and the inner wall of chamber I1 form a ring space 29 of triangular cross-section. The upper edge 3l of the chamfer and the upper edge 32 of the plunger are controlling elements to close and open the passages 23 and 24 in a predetermined `relationship as it will be explained hereinafter. Between plunger and the top shoulder 33 of the chamber I1 a compression spring 34 is inserted tending to urge the plunger downward on its seat. The plunger rod has a bore 35 forming a knee 36in the plunger body and opening in the chamfer 21 so that there is a connection between space 29 and the top portion of the extension I8 of chamber I1 when the plunger is on its seat. If, however, the plunger is in its upper end position, the top face 31 of the rod 26- bears upon surface 20 so that the top end of bore 35 is closed.

In order to explain the operation of the valve it is shown connected with its socket 3 to the delivery port of a metering pump 4I by means duit 41 and an inlet valve 4B. The pump chamber 49` is equipped with a relief valve 50 returning excess fuel to the tank 45, and, the plunger 5I is provided with a channel 52 which temporarily connects chamber 49 with delivery port 40 in the course of the plunger movement. The nozzle 43 shown attached to a cylinder head 53 comprises a needle valve 54 which can be lifted against the restraint of a strong spring 55 when the fuel entering through the channel 56 exercises sufficient pressure on the annularface 51 of a piston 58, integral with needle 54, so that the fluid can enter the cylinder 53 through orifices 59.

In Figs. `2 to 4 a valving element V is shown diagrammatically in connection with bore 8. This is done in order to indicate in Figs. 2 and 3 that the conduit from the pump 4I to the delivery valve is open, and in Fig. 4, that the conduit is closed.

Assuming that the movable parts of the system are vin the position illustrated in Fig. 1, no flow occurs from the pump 4I to the cylinder 53 because all valving elements are in closed position. Port 40 of the pump is shut by the plunger 5I the valve poppet 25 is on its seat I9; and the injector needle 54 is urged down by spring 55. Only the ring space 29 of the valve is in communication with the tank'45 through the bore 35 in the poppet 25 and its rod 26, bores I9 and I9, ring space 5, bore 9, and pipe 46. Similarly, the pipe line 44 between the valve and the nozzle is in connection with the bore I1 through the lateral conduit 2| of the valve, and passage 24. When, now, owing to the movement of the pump plunger 5I channel 52 registers with port 4D, fluid from pump chamber 49 will be forced through channel 52 and port 40 into the pipe 42.` Consequently, an' abrupt rise of pressure occurs underneath poppet 25 which will be lifted from its seat I Il against the restraint of the spring 34. However, no material flow can set in through the valve to the nozzle 43 during the first portion of the movement of the poppet because the latter still bars or obstructs, at least partly, the entrance of passage 23 as clearly shown in Fig. 2 illustrating the poppet in ak medium position. Only some fluid can escape from underneath the poppet through the bore 35, port 39, and the other parts of the drain leading back to the storage tank 45, while simultaneously, iiuid from chamber I1 whose volumetric capacity is decreased by the lift of the poppet, will be expelled through passage 24 into the line leading to the nozzle 43. In the meantime, the pressure in pipe 42 acts not only on the central bottom face 28 but also on the remainder of the poppet cross-section. This pressure accelerates the movement of the poppet which in a very short time reaches its top position shown fin Fig. 3, in which the upper end of rod 26 abuts `against face 20 of bore I8 thus closing the port 30 and the drain conduit I9. The lifting of the poppet to its end position is also assisted by the dynamic pressure built up by the increasing ow 'through the valve. During this period, passage 24 has also been closed whereas passage 23 has been completely opened owing to the movement of the control edges32 and 3|, respectively, which are spaced for this purpose a distance equal to that between the centers of the passages 23 and 24. With the poppet in its top end position, full line pressure prevails in the pipe 44 and nozzle 43 with the effect that needle 54 is lifted and fluid will be injected through orifices 59.

When, now, the plunger 5I of pump 4I continuing its upward stroke, closes port 40, a pressure drop will occur in the whole system causing spring 55 of the nozzle to urge needle 54 on its seat so that the line from the pump to the nozzle is closed at both ends. Consequently, the flow through the valve stops, and, although the pressure in the line is still high, it has become static underneath the poppet and insucient to hold the poppet in its top position. In consequence, the poppet begins to` drop, thereby opening the port 30. Simultaneously, however, also passage 24 begins to open, so that, as illustrated by Fig. 4, on the one hand the fluid under the remaining pressure in the pipe 44 can enter chamber I1 to increase the pressure urging the poppet downward while another portion can escape through passage 23 and bore 35 into the drain conduit constituted by bore I9 and from there to the tank 45. On the other hand, the pressure remaining in pipe 42 will be relieved also through bore 35 and its communication with the drain conduit. It will be apparent that this line pressure relief takes place practically instantaneously because only minute quantities of the fluid need to escape in order to drop the pressure. Hence, when the poppet has once started its downward movement,4

it will continue this movement until it is seated on surface l0. In more general terms, it may be said: When, according to communication of the pump chamber with the valve inlet, pressure acting on the poppet rises beyond the predetermined opening pressure, the valve will open abruptly against the restraint of the spring. Simultaneously, the pressure will be built up in the conduit between valve and nozzle owing to the opening of the communication between that conduit and the inlet, and assisted by the decrease of the volumetric capacity of the chamber above the piston whereby uid will be expelled into the conduitf The nozzle will open and the flow through the valve established when the pressure value in the conduit is higher than that for which the nozzle is set. As soon as the pump discontinues delivering fluid, a slight pressure drop causes the poppet to begin its downward movement, thereby opening the drain and simultaneously connecting the nozzle conduit to the agentur :space :on top of 'lthe poppetwith ytire 4 e'iie'ct'lthat @the dilerenceinpressure above andibelowlth'e `poppetwillfilce'greatly increasedfso as to abruptly close Lthe -"valve, land with @the 'ffurther feiect vIthat the-pressurein the line between the fvalvefand ftheno'zz'le willbefsuicientlyfdecreasedito prevent crests i of pressure oscillations i from reaching-'fthe value at Lwhich ifthe noz'z'le would open again for :afsecon'clary injection.

The 'embodiment of `#the y'invention illus'trate'd '-inigsi' an'df6foperates in fa lsirn'ilar manner. `-"It `comprises a substantially-cylindrical Ilhousing 560 with an axial chaniber 6| having la bttoml62. Thetop end of th'echamber` isl o'f a'v largeri diameter so as to form2a"shoul'der"6`3,fan'dfhas-aninfternal threading ,"The 'l'housing is provided *with '-threerfexternally -`threaded sockets @65, 66, 1an`df61 'ffor the attachment of connecting pipes. 'The lrfirst-'named socket `vprojects axially 'down- -Wardly,whereas the `twofothersare laterally Y'arf.

ranged. Sockets f65`andf66 havestraightfbores''6-8 :andi 69, respectively, which open Iinto thechamber "Gilfsoas to constituteiports 'lll and'Tl. '-Similarly, pocket 61 has 'a bore VY'|-2 fwhich, however, v`is fbranchedrso asto form -two'ports "13 and 14"o'f the chanibe'l on vdiierent levels. 'The'chamb'er -has two further ports Jlill and 95 connectedto eachcther'by a `conduit 16 provided inthe `Wall o'f `Ythe'housing v6|). Ahollow headed plug I|'| 'is screwed into'thethreading:6'4so as to Vbearon this position, the lpoppet `and the -housingform `fan :annular space 83 anda secondiannular space on a higher level is 'formed'byva'peripheral groove V"84 in `the upper portion of thepoppet TB. `'I'hree edges of `the poppet serve as icontrollin'g "edges with respect to 'the opening and closing 4o'f the various Pports hereinbefore mentioned, :and the yarrangement is /such that withthe poppe't 'in'its lowest position when port "10 is closed,fommuni cation exists between annularispace83 and coniduit '69 of "socket-'66 through port '94, 'conduit T6, i"

'port '95, groove 84 'and port "H Simultaneously, conduit .12 cf .socket 61 communicates with fthe space Aoi 'chamber'l on top of poppet'19 'through port '.1'4. When the poppet .moves upward. .the lowest ponpet edge .85 begins 'to .open port 113 Whereas .simultaneously edge 586, which 'is lthe lower one adjacentto.groove 8.4;and'the top edge '81 o'f the'poppe't close the ports 95 and 14 respectively, at .the same rate, so 'that when lthe poppet in itshighestposition abuts against shoulder 18, the vchamber space above thepoppet has no outside connection, port 'T4 'being .closed "by pcppetzone 88, and the .chamber space'belowlthe vpuppet is'in connection withpthe conduits 'B8 and V"l2, port 13 being opened and port 95 being closed ;f

by poppet zone 89.

It will be apparentthat this valve Qperatesin substantially the same manner as, and `can'lbe substituted for, the first `described valve .inthe system illustrated v.in Fig. 1, if sockets 55,165., .61

vare respectively connected to the pipes ".42, '45, and 44.

Whereas in the *two embodiments 'first described 'the space orfchamber portion .underneath the puppet has ports for communication with lll) lli)

f of Ythe poppet.

Sthe deliveryi'cotdutzandiwith :ith'e drain fconfdui't, 'lthe'ipurposeicff-theiinventionleanoeaccomplished .alsovwi'th a'valv'e in'whidh't'h'e space 'above th'e puppetfisrprovidediwiththe mentioned two kinds ccfzportsiand the span;1 "lowthepcppet is proivid'ediwith 'merelyfaniii'rlet a'nda delivery port. ..Tni'siis showniby the embodiment.illustratedain Figs. 7 and 8. In this embodiment, thfe val've `-housing llllll-i'slp'art -oflamachinesu'chiaslafpump tofwhich iitheva'lve maybe applied. JfHoWever, .itis tofbe'iunderstnod that theh'ousng fm'ay'be isepar'ateLpiece fas iin the :case of Etlie embodimerits rst de's'cribe'd, for conversely in 'the i case -o'f :embodiments .'.illustrate'd'in rFi'g's. .1 to 16, :the 'housing may Tbe constructed fas integral fwith .-a :machine :for whichrth'e fvalve eis destined. -'Hous- :ing |190 is formed as a Fsubstantiall'y cylindrieal 'projection Ihaving afstepped bore with fa 'bottom face nel ,.afrst :annular `rshmilcler @|02 :and fais-ec- .onrd .rannularfshoulder 111653. flh'eitop end of the ihousingistextemallyfthreadedTat I 0'4. inlconduit t|1l5with .port |116 rop'ensfaxially in bottom IUI .and another '.condutml'l has ra `:port M118 in :wall :between l:the 'itwo fshoulders fm2 :and 103. Conduit 11?@5 'iis fdestned to Lbe connected `as :the inl t :pf sa fluid runder :high i pressure, f 'and conduit 5ml is :a fdrain conduit Heading i-rorn 4the 'valve to fa space ".(lnotrshown') where relatively low pressure prevails :plug-'like rbcdy @H19 :is iin- :sertedin th'e'housingiso as tofseattiglitlydonthe bottom face IDI and to tlthe fwalloffthe lowest interior housing portion I |0 underneathfsl'oulder fm2. ,The'plug ftsialsoiinto th'e'tophcusing p'ortion |Il| lwith :"a ange 1T|I| 2 .bea'ring lvon islioul'de'r :I 03 zand?from'lwhi'chianrexternally threadedl'socket |'|3projjects'upwardfin axial :direction A cap nut `1l :engages 'the `r'threading :|94 'and lurges the'fliangel ||2 and thusfthe .plug body `-'I'l Son its seat. An annular :space l|f|`5 is folrmed by 'fthe 'described structure 'of fthe plugf and -the 'housing wall :between fthe shoulders |62 and |03. The plug is y provided iwi-th fairel'atively wide faxiall bore ||6 of ccnstantfdiameter 'from thefbottom upward approximately :as ifar as ithe fflange 2| |12.

Laterally o'f 1Ab'ore '116, a narrow -conduit |41 reachesalso from the bottom :upwards and `opens with a s'lan'ting =porticn "'|f|8 Aiin' a top vrecess Y|"|9 o'fthe socket H3. Ailcwerpassafge'nll with port ill-2|, and lan upper tpassage |22 with port `|2`3, connect the bores ||6 and ll'l, port `|$3 'ibe'ing arranged -immediately underneath 'the top surface LISZA o'fthe bore f'| |56. `Iriteri/orlyo'f bore H6 a'hollow piston |525-orvpoppeft is vurgeddownward by a spring |26 bearing :against face y:|1211 Tand itsv bottom sur-face Alf2-'9 of :reduced "diameter closes `port lDB. "The lower iport'ion --c'f the ypoppet is 'hamfere'd so A'as toform fa triangular Aring space -530 'in fb'ore underneath the control edge |3'| which cooperates'with port y|`f23|. 'The 'poppet fis also provided -with a peripheral control groove |32 which 'has an opening |33 into the interior This groove cooperates with la port |34 'ci a passage |'35-which-extends thro-ugh the-wall'oithe-pluginto'the ring space H5. The arrangement of the controlling elements issuch that 'in the V'illustrated `position 'in which inlet port |196 is 'c1osed,`.control edge |3| is underneath port |25, `groove V.|33 underneathport |34, and the top edge |3`6'of the poppet underneathport |23. Hence, there is only communication between thespace above thegpoppe'tandcondu'it LHS. In the other end.position,.i. e.,V when the top rim Y|36 o'f Ythepoppet,bearsagainst surface |224, .port |23 will 'be closed, the groove` |3'2 will register with port' |34,` and thezedge r|'c|"wi.l1 vbie above portpl2l. In consequence,.vthe upper portion of the space above the poppet, or more correctly, the space between the two surfaces .|24 and |23,

will be in communication .with the drain conduit.

|01, and the space underneath the poppet Will connect the inlet conduit |05 with the delivery conduit It Will be apparent thatin the embodiment just described, pressure relief of the delivery conduit ||8 occurs via port |23, space HS, groove |32, port |35, space I|5 and drain |01. The pressure of the inlet conduit |05 will be relieved during the closing movements of the valve through space |30, port |2I, passages. |20 and H1, and further on the same way as explained in connection with the delivery conduit. It will also be seen that after the closing of the valve the pressure remaining in conduit ||8 Will build upon top of the poppet |25 in addition to the spring pressure.

In all other respects, particularly in the effect of preventing pressure oscillations in the connected lines from reaching dangerously high crests, the described embodiments operate in a similar manner. Many alterations and modications Vof the structures hereinbefore described will be -apparent to those skilled in the art and may be made without departing from the spirit and essence of the present invention which, for this reason, shall not be limited but by the scope of the appended claims.

Iclaim:

1. A delivery valve comprising a casing with two chambers therein, the first one of said chambers having an inlet port, delivery port and a drain port, the second chamber having a connecting port communicating with said delivery port, a poppet being movable in both said chambers and having two end positions, said poppet being so arranged `and constructed as to open said inlet and delivery ports and to close said drain port and said connecting port, when moving from its rst to its second end position, and to close said inlet and delivery ports andl to open said drain port and connecting port when moving -lrom its second to its rst end position, and a spring in said second chamber and bearing-on said poppet so as to tend to urge said poppet into its irst position against an existing inlet pressure.

2. A delivery valve comprising a casing with a chamber therein, a poppet movable in said chamber so as to divide said chamber into a rst and a second part on top and. below said poppetrespectively, said first part chamber having an inlet port, a delivery port and a drain port, said second part chamber having a connecting port communicating with said delivery port, said poppet having two end positions and beingso constructed and arranged as to open said 'inlet and delivery ports and to close said drain port and connecting .port when moving from its rst to its second position, and to close said inlet and delivery ports 4and to open said drain port and connecting port when moving from its second to its first end positiornand a spring in said second part chamber and bearing on said puppet so as to tend to urge said poppet into its iirst position against an existing inlet pressure,

3. A delivery valve comprising a casing with three chambers therein, the first one of said chambers having an inlet port and a delivery port, said second chamber having la connecting port communicating vwith said delivery port, said third chamber being of a smaller volumetric Vicapacity than either: one :of ethe 'other' chambers, andyha-vin'gfa drain port, a passage from said -rst vto said; third chamberga poppet movable in said three chambers and having two end positions,;-said poppet beingsfo constructed and-anranged asto fopen, said inlet. anddeliverygports and to close said connectingport and said.L passage'when moving from its first ,end position into the second, and to open said passagek and said connecting port, and to closesaid.delivery and inlet ports whenmoving `from itssecond into its iirst positiomand a spring in one of -said Vchambers* and bearing onsaid poppet so asi to ying operative in said second chamberysaid rst part `chamberhaving an inlet and a delivery port, said second part'chamber having a; con'- nectingportin communication with said deliver;r

port, .said second chamberhaving a `drain port.

apassage from said-,first part chamber to said second chamber, said poppet being so constructed and arranged thatsaid body will -lopen -said inlet and delivery ports tandkl close said -connecting port and said rod-will close said drain port when the poppet vmoves fromV its `first .to its second position, and that the body Willclose the inlet and,deliveryportsand open the connecting -port and the rod Will open the drain port whenythe poppet moves from its second toits first position, and a spring insaid second part chamber andbearing on said body sofas to tend to-urge said poppet into its first end position. Y n

.5.-.A delivery valve lcomprising a casing with two cylindrical and co-axial chambers therein, the second chamber having a smaller diameter than the first chamber, an inlet port in the bottom and a delivery port in the side wall of.,said iirst chamber, a drain port at the top of said secondchamber anda conduit between -said iirst andsaid second chamber, apoppet includinga stepped plunger, having a -iirst portion operative in said rst chamber and a secondportion operative in said second` chambensaid rst plunger portion havingat its bottom a valving surface in relation to saidinletport and a control edge of. its side. wall in relation to said delivery port, andV said second plunger portion being in .valving relation to saiddrain port to close said drain port when said first plunger portion hascompletely opened said inletand delivery ports.

6. A valve as claimed in lclaim 5 further comprising a connecting port in said iirst chamber in .communication with said delivery port, and a second control edge of said firstplunger portion positioned in relation to said connecting port so as to close said connecting port .while said iirst edge opens said delivery port.

f7.v A valve as` claimedin claim 5 wherein said conduit between said rst and said second chamber is provided by a bore in said plunger from its bottom laterally of said valving surface to the free end of said second plunger portion.

8. A delivery valve comprising a substantially hollow cylindrical casing open at its top and provided with an internal threading at its upper portion, a substantially cylindrical plug including a head and a body, the upper body portion being externally threaded and screwed into said casing so as to seat tightly on the bottom of said casing, and to form an annular space between its lower portion and said casing, said casing having an inlet port in its bottom and a drain conduit in communication with said annular space, said plug having in its body portion a stepped axial bore wider in its lower portion than in its top portion, so as to form two communicating chambers, a drain passage between said top chamber and said annular space, and a delivery conduit laterally of said bore and with a delivery port and a connecting port, the latter above the former, in the side wall of said lower chamber, and a spring-loaded poppet operative in both chambers and, positioned in relation to said ports and said drain passage, so as to close said passage and said connecting port while said inlet and delivery ports are completely opened.

9. In a valve of the type described, a plug-like body having a flat bottom surface and embodying means to secure said body in a housing with a tight t of its bottom surface therein, said body being provided with a central bore from its bottom through a portion of its length, and with a plurality of ports opening into said central bore, two of said ports being arranged on different levels and in communication with a delivery conduit and one of said ports being in connection with a drain conduit, and a springprovided piston-like poppet in said central bore, said poppet having a bottom surface of a diameter smaller than that of said central bore and formed as a valving surface exposed to a pressure acting against it, said poppet also embodying controlling edges in operative relation to said ports.

10. A delivery valve comprising a housing open on top, a member in closing connection with said housing, an inlet port in the bottom surface of said housing, a delivery port, a drain port and a connecting port all in said housing on diierent levels, a piston movable in said housing and having a bottom surface in valving relation to said inlet port, and three control edges in operative relation to said last mentioned three ports, respectively, so as to close said drain port and said connecting port simultaneously with the opening of said inlet port and said delivery port, and a spring between said closing member and said poppet so as to urge said poppet in a position to close said inlet and said delivery port.

11. A delivery valve comprising a housing having an inlet port in its bottom, a delivery port, a drain port, and a connecting port in communication with said delivery port, said last mentioned three ports being arranged on different levels, a hollow piston-like poppet open at its top and being movable in said housing, said poppet having a bottom face of a diameter smaller than that of the major poppet portion, two controlling edges, and a peripheral groove with an opening into the hollow of said poppet, said edges being in cooperative relation to said delivery port and said connecting port respectively, and said groove being in cooperative relation to said drain port, so as to establish communication between said inlet port and said delivery port, and between said drain port and the hollow space of the poppet, and to close said connecting port when the poppet moves in the one direction, and to close said inlet port, said drain port, and said delivery port, and to establish communication between said connecting port and the interior space of the poppet when the latter moves in the opposite direction.

LOUIS BEEH. 

